Radar power supply system



Patented June 30, 1953 RADAR IOWER SUPPLY SYSTEM 7 Harold S. Gr. Cooper, Cambridge, and Howard Louis Schultz, Wellesley, Mass., assignors, by mesne assignments, to the UnitedStates of Americaas represented by the Secretary of War Application March 22, 1945, Serial 1%. 584,236

4 Claims. (Cl. 250-27) This invention relates to a communication system and particularly to a power supply for a radio receiver of pulse modulated radio signals used in radio direction and ranging systems.

The plate supply voltage for radio tubes must be of positive polarity and constant magnitude for normal operation. Batteries may be used for smaller receivers but they are not practical as a power supply for larger receivers or for operation over long periods'of time. It is customary, therefore, to utilize a source of alternating voltage, which is rectified and filtered providing the necessary direct voltage for the radio tubes. Rectifications and filter circuits and components necessarily. add to the weight and power requirements.

r Accordingly, it is an object of this invention to provide a power supply for a radio receiver operating on new and improved principles.

Other objects are to reduce weight, to eliminate the components of the receiver required to form D. C. voltage, to operate vacuum tubes on A. C. voltage, and to reduce the power required for a radio receiver.

Other objects will be apparent to those skilled in the art after a study of the following specification, claims and drawing in which:

Fig. 1 is a diagram of a radio receiver using the principles of this invention; and

Fig. 2 shows thewaveform of the power supply output.

Referring now more particularly to Fig. 1 there is shown in partial block diagram form the various stages ofa radio receiver of the type used in radio direction and ranging systems. Receivers of this type usually consist of a mixer stage, a local oscillator, one or more I. F. stages, a second detector, a video stage and an indicator.

. According to the principles of this invention the power supply for such a receiver consists of a power transformer 4 which is connected tota source of alternating current potential. Across the secondary of transformer 6 there is connected a voltage regulator tube '5 in series with a second voltage regulator tube 5. These voltage regulator tubes are the gas-filled type well known in the art.

The output of voltage regulator tube 5 is connected by lead 9 direct to the plate circuit of one stage of the receiver illustrated as I. F. tube 1. Since other stages of the receiver may require a ,difierent and greater voltage there is shown a lead It connecting the combined output of tubes 5 and 6 to the plate circuit of tube 8 in the video stage. .The A. C. source may produce a level-off polarity as applied. Since the voltage across the discharge tube remains substantially constant for considerable range of discharge current the voltage output will level off across a limited portion of the sine wave. Thus the tube will suddenly conduct as the sine wave is applied and at a certain. point will level on for a limited period of time and then discharge will cease. When the output of the regulator discharge tube is applied to the radio circuit, receiving tubes 1 and 8 will receive a voltage substantially constant in magnitude at periodic intervals during the flat portion of each cycle.

A period of substantially constant voltage during which the tube freely discharges may be in the order of 500 microseconds for an A. C. supply voltage of 400 cycles per second.

The transmitter 2 for use with the receiver above described operates from the same power source of alternating current at a pulsing repetition rate which is synchronous therewith. Since the receiver tubes are activated at periodic intervals as explained above, the time of transmission of each pulse must be regulated according to the time the receiver is sensitive for reception.

The method of regulating the time of pulse transmission is known in the art and commonly practiced in many radar transmitters and will not be described here.

The pulse transmission takes place at a time generally corresponding to point A on the wave form shown in Fig. 2. This is the point at which the voltage supply will level off sufiiciently for receiver tube operation. The receiver is then in a condition to receive for a limited period of time after the transmision of a pulse. In effect the power supply furnishes both an operating and a gating potential simultaneously for the receiver.

In radio direction and ranging operation, a supply voltage of 400 cycles per second will permit a useful range of approximately 50 miles, since the time of a complete cycle is 2,500 microseconds corresponding to about 200 miles.

With the operation described above the power "that in accordance with the present invention there is shown in a radar system transmitting pulses of energy and receiving echo reply pulses during a chosen time interval recurrently at a regular repetition rate, an electronic receiver and a source of operating and "gating potential for elements of the receiver comprising a source of alternating voltage synchronous with the repetition. Also provided are means comprising aplurality of series connected voltage; regulating devices in parallel with the alternating voltage. source for limiting in at least one polarity the amplitude of the voltage to a corresponding plurality of constant values during a time in each cycle corresponding to the chosen time interval and means for utilizing the constant values of voltage to provide operating and gating potentials to elements in the receiver. v

What has been described is a preferred em'bodiment of this invention. It will be apparent to those skilled in the art that many variations are possible without departing from the scope of the invention.

What isclaimedis:

1. In a radar system transmitting pulses of energy and receiving echo reply pulses during a chosen time interval reourrently at a regular repetition rate, an electronic receiver for said echo pulses, a source of operatingand gating potentials for elements of said receiver comprising a source of alternating voltage synchronous with said repetition rate, means comprising a plurality of series connected voltage regulating devices in parallel with said alternating voltage source for limiting in at least one. polarity the amplitude of said voltage to a corresponding plurality of contentials for elements of said receiver comprising a source of alternating voltage synchronous with said repetition rate, means comprising a plurality of voltage regulating devices for limiting in at least one polarity the amplitude of said voltage to a corresponding plurality of constant values during a: time in each cycle corresponding to said interval, and means for utilizing said constant values of voltageto directlyprovide operating and gating potentials for elements in said receiver.

' 3. In a radar system transmitting pulses of energy and receiving echo reply pulses duringa chosen time interval recurrently at a regular repetition rate, an electronic receiver for said echo pulses a source of operating and gating potential for elements of said receiver comprising a source of alternating voltage synchronous with said repetition rate, means comprising a regulating device for limiting in at least one polarity the amplitude of said voltage to a constant value during a time in each cycle corresponding to said interval, and means 'for utilizing said constant value of voltage to directly provide operating and gating potentials'for elements in said receiver.

l. In a radar system transmitting pulses of energy and receiving echo reply pulses during a chosen time interval recurrently at a regular repetition rate, an electronic receiver for said echo pulses, a source of operating and gating potential fo elements of said receiver comprising a source of alternating voltage synchronous with said repetition rate, means comprising a voltage regulating device for limiting in at least one polarity the amplitude of said voltage to a'constaht value during a time in each cycle corresponding to said interval, andmeans for'utilizing said constant value of voltage to directly provide an operating and gating potential for an element in said receiver.

HAROLD s. G. COOPER.

HOWARD LOUIS SCHULTZ. References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,055,883 Terry Q Sept. 29, 1936 2,059,004 Leeds Oct. 27, 1936 2,141,654 Kott Dec. 27, 1938 2,220,183 Ulbricht Nov. 6, 1940' 2,454,810 Labin NOV. 30, 1943 

